Use GDAL API to determine multi-layer extensions on GDAL 3.4+

qgis · Aug 7, 2021 · c986c1a · c986c1a
1 parent bdc5b84
commit c986c1a
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Showing 5 changed files with 111 additions and 27 deletions.
diff --git a/src/core/providers/gdal/qgsgdalprovider.cpp b/src/core/providers/gdal/qgsgdalprovider.cpp
@@ -3611,7 +3611,7 @@ QList<QgsProviderSublayerDetails> QgsGdalProviderMetadata::querySublayers( const
     details.setProviderKey( QStringLiteral( "gdal" ) );
     details.setUri( uri );
     details.setName( QgsProviderUtils::suggestLayerNameFromFilePath( path ) );
-    if ( QgsGdalUtils::SUPPORTED_DB_LAYERS_EXTENSIONS.contains( suffix ) )
+    if ( QgsGdalUtils::multiLayerFileExtensions().contains( suffix ) )
     {
       // uri may contain sublayers, but query flags prevent us from examining them
       details.setSkippedContainerScan( true );

diff --git a/src/core/providers/ogr/qgsogrprovidermetadata.cpp b/src/core/providers/ogr/qgsogrprovidermetadata.cpp
@@ -1146,7 +1146,7 @@ QList<QgsProviderSublayerDetails> QgsOgrProviderMetadata::querySublayers( const
       details.setProviderKey( QStringLiteral( "ogr" ) );
       details.setUri( uri );
       details.setName( QgsProviderUtils::suggestLayerNameFromFilePath( path ) );
-      if ( QgsGdalUtils::SUPPORTED_DB_LAYERS_EXTENSIONS.contains( suffix ) )
+      if ( QgsGdalUtils::multiLayerFileExtensions().contains( suffix ) )
       {
         // uri may contain sublayers, but query flags prevent us from examining them
         details.setSkippedContainerScan( true );

diff --git a/src/core/qgsgdalutils.cpp b/src/core/qgsgdalutils.cpp
@@ -22,32 +22,13 @@
 #include "gdal.h"
 #include "gdalwarper.h"
 #include "cpl_string.h"
+#include "qgsapplication.h"
 
 #include <QNetworkProxy>
 #include <QString>
 #include <QImage>
 #include <QFileInfo>
-
-// File extensions for formats supported by GDAL which may contain multiple layers
-// and should be treated as a potential layer container
-const QStringList QgsGdalUtils::SUPPORTED_DB_LAYERS_EXTENSIONS
-{
-  QStringLiteral( "gpkg" ),
-  QStringLiteral( "sqlite" ),
-  QStringLiteral( "db" ),
-  QStringLiteral( "gdb" ),
-  QStringLiteral( "kml" ),
-  QStringLiteral( "kmz" ),
-  QStringLiteral( "osm" ),
-  QStringLiteral( "mdb" ),
-  QStringLiteral( "accdb" ),
-  QStringLiteral( "xls" ),
-  QStringLiteral( "xlsx" ),
-  QStringLiteral( "gpx" ),
-  QStringLiteral( "pdf" ),
-  QStringLiteral( "pbf" ),
-  QStringLiteral( "nc" ),
-  QStringLiteral( "shp.zip" ) };
+#include <mutex>
 
 bool QgsGdalUtils::supportsRasterCreate( GDALDriverH driver )
 {
@@ -564,6 +545,90 @@ bool QgsGdalUtils::pathIsCheapToOpen( const QString &path, int smallFileSizeLimi
   return false;
 }
 
+QStringList QgsGdalUtils::multiLayerFileExtensions()
+{
+#if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(3,4,0)
+  // get supported extensions
+  static std::once_flag initialized;
+  static QStringList SUPPORTED_DB_LAYERS_EXTENSIONS;
+  std::call_once( initialized, [ = ]
+  {
+    // iterate through all of the supported drivers, adding the corresponding file extensions for
+    // types which advertise multilayer support
+    GDALDriverH driver = nullptr;
+
+    QSet< QString > extensions;
+
+    for ( int i = 0; i < GDALGetDriverCount(); ++i )
+    {
+      driver = GDALGetDriver( i );
+      if ( !driver )
+      {
+        QgsLogger::warning( "unable to get driver " + QString::number( i ) );
+        continue;
+      }
+
+      bool isMultiLayer = false;
+      if ( QString( GDALGetMetadataItem( driver, GDAL_DCAP_RASTER, nullptr ) ) == QLatin1String( "YES" ) )
+      {
+        if ( GDALGetMetadataItem( driver, GDAL_DMD_SUBDATASETS, nullptr ) != nullptr )
+        {
+          isMultiLayer = true;
+        }
+      }
+      if ( !isMultiLayer && QString( GDALGetMetadataItem( driver, GDAL_DCAP_VECTOR, nullptr ) ) == QLatin1String( "YES" ) )
+      {
+        if ( GDALGetMetadataItem( driver, GDAL_DCAP_MULTIPLE_VECTOR_LAYERS, nullptr ) != nullptr )
+        {
+          isMultiLayer = true;
+        }
+      }
+
+      if ( !isMultiLayer )
+        continue;
+
+      const QString driverExtensions = GDALGetMetadataItem( driver, GDAL_DMD_EXTENSIONS, "" );
+      if ( driverExtensions.isEmpty() )
+        continue;
+
+#if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
+      const QStringList splitExtensions = driverExtensions.split( ' ', QString::SkipEmptyParts );
+#else
+      const QStringList splitExtensions = driverExtensions.split( ' ', Qt::SkipEmptyParts );
+#endif
+
+      for ( const QString &ext : splitExtensions )
+        extensions.insert( ext );
+    }
+
+    SUPPORTED_DB_LAYERS_EXTENSIONS = qgis::setToList( extensions );
+  } );
+  return SUPPORTED_DB_LAYERS_EXTENSIONS;
+
+#else
+  static const QStringList SUPPORTED_DB_LAYERS_EXTENSIONS
+  {
+    QStringLiteral( "gpkg" ),
+    QStringLiteral( "sqlite" ),
+    QStringLiteral( "db" ),
+    QStringLiteral( "gdb" ),
+    QStringLiteral( "kml" ),
+    QStringLiteral( "kmz" ),
+    QStringLiteral( "osm" ),
+    QStringLiteral( "mdb" ),
+    QStringLiteral( "accdb" ),
+    QStringLiteral( "xls" ),
+    QStringLiteral( "xlsx" ),
+    QStringLiteral( "ods" ),
+    QStringLiteral( "gpx" ),
+    QStringLiteral( "pdf" ),
+    QStringLiteral( "pbf" ),
+    QStringLiteral( "nc" ),
+    QStringLiteral( "shp.zip" ) };
+  return SUPPORTED_DB_LAYERS_EXTENSIONS;
+#endif
+}
+
 bool QgsGdalUtils::vrtMatchesLayerType( const QString &vrtPath, QgsMapLayerType type )
 {
   CPLPushErrorHandler( CPLQuietErrorHandler );

diff --git a/src/core/qgsgdalutils.h b/src/core/qgsgdalutils.h
@@ -148,13 +148,13 @@ class CORE_EXPORT QgsGdalUtils
      */
     static bool pathIsCheapToOpen( const QString &path, int smallFileSizeLimit = 50000 );
 
-
     /**
-     * File extensions for formats supported by GDAL which may contain multiple layers
-     * and should be treated as a potential layer container.
+     * Returns a list of file extensions which potentially contain multiple layers representing
+     * GDAL raster or vector layers.
+     *
      * \since QGIS 3.22
      */
-    static const QStringList SUPPORTED_DB_LAYERS_EXTENSIONS;
+    static QStringList multiLayerFileExtensions();
 
     /**
      * Returns TRUE if the VRT file at the specified path is a VRT matching

diff --git a/tests/src/core/testqgsgdalutils.cpp b/tests/src/core/testqgsgdalutils.cpp
@@ -43,6 +43,7 @@ class TestQgsGdalUtils: public QObject
     void testResampleImageToImage();
     void testPathIsCheapToOpen();
     void testVrtMatchesLayerType();
+    void testMultilayerExtensions();
 
   private:
 
@@ -294,6 +295,24 @@ void TestQgsGdalUtils::testVrtMatchesLayerType()
   QVERIFY( QgsGdalUtils::vrtMatchesLayerType( QStringLiteral( TEST_DATA_DIR ) + "/vector_vrt.vrt", QgsMapLayerType::VectorLayer ) );
 }
 
+void TestQgsGdalUtils::testMultilayerExtensions()
+{
+  const QStringList extensions = QgsGdalUtils::multiLayerFileExtensions();
+  QVERIFY( extensions.contains( QStringLiteral( "gpkg" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "sqlite" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "db" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "kml" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "ods" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "osm" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "mdb" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "xls" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "xlsx" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "gpx" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "pdf" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "nc" ) ) );
+  QVERIFY( extensions.contains( QStringLiteral( "gdb" ) ) );
+}
+
 double TestQgsGdalUtils::identify( GDALDatasetH dataset, int band, int px, int py )
 {
   GDALRasterBandH hBand = GDALGetRasterBand( dataset, band );